-er a-a a-b a-i aaa aab aad aae aai aan aar ab- aba abb abd abe abi abn abr ad- ada adb add ade adi adn adr aea aeb aed aee aei aen aer ai- aia aib aid aie aii ain air an- ana anb and ane ani ann anr ar- ara arb ard are ari arn arr baa bab bad bae bai ban bar bba bbb bbd bbe bbi bbn bbr bda bdb bdd bde bdi bdr be- bea beb bed bee bei ben ber bi- bia bib bid bie bii bin bir bna bnb bnd bne bni bnn bnr bra brb brd bre bri brn brr daa dab dad dae dai dan dar dba dbb dbd dbe dbi dbn dbr dda ddb ddd dde ddi ddn ddr de- dea deb ded dee dei den der di- dia dib did die dii din dir dna dnb dnd dne dni dnn dnr dra drb drd dre dri drn drr eaa eab ead eae eai ean ear eba ebb ebd ebe ebi ebn ebr ed- eda edb edd ede edi edn edr eea eeb eed eee een eer eia eib eid eie eii ein eir en- ena enb end ene eni enn enr era erb erd ere eri ern err i-d ia- iaa iab iad iae iai ian iar iba ibb ibd ibe ibi ibn ibr ida idb idd ide idi idn idr ie- iea ied iee iei ien ier iia iib iid iie iii iin iir in- ina inb ind ine ini inn inr ir- ira irb ird ire iri irn irr n-i naa nab nad nae nai nan nar nba nbb nbd nbe nbi nbn nbr nda ndb ndd nde ndi ndn ndr ne- nea neb ned nee nei nen ner nia nib nid nie nii nin nir nna nnb nne nni nnn nra nrb nrd nre nri nrn nrr ra- raa rab rad rae rai ran rar rba rbb rbd rbe rbi rbn rbr rda rdb rdd rde rdi rdn rdr re- rea reb red ree rei ren rer ria rib rid rie rii rin rir rna rnb rnd rni rnn rnr rra rrb rrd rri rrn rrr